Eur. Phys. J. B (2018) 91: 36
https://doi.org/10.1140/epjb/e2018-80536-8

Regular Article

Strong electron–phonon interaction and colossal magnetoresistance in EuTiO₃

Department of Physics, National University of Singapore, Singapore 117551, Republic of Singapore

^a e-mail: a0112308@u.nus.edu

Received: 21 September 2017
Received in final form: 2 December 2017
Published online: 12 February 2018

Abstract

At low temperatures, EuTiO₃ system has very large resistivities and exhibits colossal magnetoresistance. Based on a first principle calculation and the dynamical mean-field theory for small polaron we have calculated the transport properties of EuTiO₃. It is found that due to electron–phonon interaction the conduction band may form a tiny polaronic subband which is close to the Fermi level. The tiny subband is responsible for the large resistivity. Besides, EuTiO₃ is a weak antiferromagnetic material and its magnetization would slightly shift the subband via exchange interaction between conduction electrons and magnetic atoms. Since the subband is close to the Fermi level, a slight shift of its position gives colossal magnetoresistance.